Luer lock connectors are used in many biomedical systems to couple two fluid carrying tubes. A major advantage of these connectors is their lockable coupling-decoupling feature that can be easily manipulated by a single user. The connectors themselves comprise standardized mating conical coupling surfaces (e.g. ISO 594, 80369) designed to prevent leaks under normal operating pressures, which are relatively low (typically below 300 kPa). The locking feature comprises a double start right handed female threaded nut on one connector that locks on to a corresponding male thread or lug feature on the other connector.
Unfortunately, luer-lock (and other locking) connectors often cause significant problems when the axial forces are excessive. An example of this is associated with the use of catheters for collecting a fluid in a bag for future disposal. Since the collection bag may need to be replaced well before the catheter itself, a typical arrangement comprises a catheter-tubing assembly and a collection bag-tubing assembly that are coupled together using luer-lock connectors. In this situation, a significant axial/pulling force on the overall assembly can occur if the tubing gets caught or tangled up accidentally in clothing, limbs, bedding, or other similar objects. This can result in the catheter being pulled out of the body causing injury and harm to the patient.